Impairment-to-Disability Ratings; The Mechanics

Sunday, November 21, 2004 | 0

Effective 1/01/05 the new California permanent disability rating schedule should be in use. Based on the AMA Guides, 5th Edition, the new schedule applies to all dates of injuries for which a Permanent and Stationary (P&S)/Maximum Medical Improvement (MMI) report has not been issued by a Primary Treating Physician (PTP), Agreed Medical Examiner (AME) or Qualified Medical Examiner (QME). The following is an examination of the mechanics of the new rating system.

PTP/QME/AME - Vocational Evaluation Responsibilities

The physician whose duty it is to determine the permanent impairment has certain responsibilities under the code and regulations.

1) Evaluates the injured worker and provides a whole person impairment percentage for ratings addressing only a single body part (e.g., joint), spinal segment (e.g., cervical spine) or body system (e.g., hearing). a) For a single body part or body system - physician provides the Impairment Rating % as a whole person percentage.

b) For multiple joints within an extremity (not fingers or toes), multiple body parts or organ systems, physician provides a single body part % or regional impairment %.
i) Upper Extremities: Right wrist, right shoulder, hand, and both elbows.
ii) Lower Extremities: Left ankle, right knee, bilateral hips.
iii) Spine: Cervical, Thoracic, Lumbar or Pelvis
2) Uses AMA Guides rating criteria and AD/WCAB California Code of Regulation Guidelines addressing reporting requirements of the P&S/MMI report.

a) Fully explains the basis of the impairment rating determination and its corresponding criteria.
b) Lists all chart tables, AMA Guides pages numbers used in the IR determination and Provides Rationale for all opinions.
c) Uses AMA Reporting Forms.

3) Provides both Vocational & Medical Modifiers: Work restrictions and loss of pre-injury capacity are no longer ratable but are still required. For job modifications and accommodations purposes, evaluating physician must provide both medical and vocational modifiers. Both types of modifiers must be supported by the impairment findings including work activities. A job description or vocational functions analysis should help the physician address the following issues:

a. Q: Are the current impairment levels precluding the injured worker from performing the usual and customary duties - essential (vocational) functions of his occupation?
b. Q: Could the injured worker or co-workers be vulnerable, if modifications or accommodations are not provided?
i. For example- Due to a diagnosis of vertigo, employee can no longer work on unprotected scaffolding.

Vocational Impairment & Disability Workers Compensation Rating Specialist

The rating specialist will have certain standards and duties relative to rendering a permanent disability rating under the new system:

1. Follow the rating principles established by LC 4660's implementing instrument, The Schedule for Impairment-to-Permanent Disability (PD).

2. Insure that AMA impairments are properly transmuted into the proper disability rating formula.

3. Corrects mathematical impairment rating errors, requests clarification or returns incomplete medical reports.

4. Converts AMA whole person impairment rating percentage into a single body part or regional percentage before applying the correct Earning Capacity (EC) modifier and the adjustments for age and occupation.

After proper modifications, an AMA Impairment Rating Percentage (IR%) is the only base for determining a California permanent disability percentage. We no longer rate subjective factors of disability based on analogies to rating standards. We no longer rate work restrictions or work capacity functional loss.

Psychiatric Disability

Along with the overall changes to rating disabilities under the new system, profound changes are made to the rating of psychiatric disabilities.

The Division of Workers Compensation has replaced the current psychiatric evaluation method with the Global Assessment of Functioning (GAF Scale). This Scale is included in the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR), in the section on multi-axial assessments. Correlations to Whole Person Impairment Rating percentage will be part of the new schedule.

The GAF Scale is an 11-category, 100-point scale, which is widely used in adult psychiatric practice and research. Unlike the 8-work functions, it makes a clear distinction that the evaluating physician must not consider or include impairments in function due to physical or environmental limitations.

The Scoring ranges are as follows:

1. 91-100: Superior functioning in a wide range of activities, life's problems never seem to get out of hand, is sought out by others because of his or her many positive qualities. No symptoms.
2. 81-90: Absent or minimal symptoms (e.g., mild anxiety before an exam), good functioning in all areas, interested and involved in a wide range of activities, socially effective, generally satisfied with life, no more than everyday problems or concerns (e.g., an occasional argument with family members).
3. 71-80: If symptoms are present, they are transient and expectable reactions to psychosocial stressors (e.g., difficulty concentrating after family argument); no more than slight impairment in social, occupational, or school functioning (e.g., temporarily falling behind in schoolwork).
4. 61-70: Some mild symptoms (e.g., depressed mood and mild insomnia) OR some difficulty in social, occupational, or school functioning (e.g., occasional truancy, or theft within the household), but generally functioning pretty well, has some meaningful interpersonal relationships.
5. 51-60: Moderate symptoms (e.g., flat affect and circumstantial speech, occasional panic attacks) OR moderate difficulty in social, occupational, or school functioning (e.g., few friends, conflicts with peers or co-workers).
6. 41-50: Serious symptoms (e.g., suicidal ideation, severe obsessional rituals, frequent shoplifting) OR any serious impairment in social, occupational, or school functioning (e.g., no friends, unable to keep a job).
7. 31-40: Some impairment in reality testing or communication (e.g., speech is at times illogical, obscure, or irrelevant) OR major impairment in several areas, such as work or school, family relations, judgment, thinking, or mood (e.g., depressed man avoids friends, neglects family, and is unable to work; child frequently beats up younger children, is defiant at home, and is failing at school).
8. 21-30: Behavior is considerably influenced by delusions or hallucinations OR serious impairment in communication or judgment (e.g., sometimes incoherent, acts grossly inappropriately, suicidal preoccupation) OR inability to function in almost all areas (e.g., stays in bed all day, no job, home, or friends).
9. 11-20: Some danger of hurting self or others (e.g., suicide attempts without clear expectation of death; frequently violent; manic excitement) OR occasionally fails to maintain minimal personal hygiene (e.g., smears feces) OR gross impairment in communication (e.g., largely incoherent or mute).
10. 01-10: Persistent danger of severely hurting self or others (e.g., recurrent violence) OR persistent inability to maintain minimal personal hygiene OR serious suicidal act with clear expectation of death.
11. 0: Inadequate information.

The New Rating Formula- Impairment-to-Disability Rating Mechanics After 01-01-2005

The following table explains the PD rating method under the new schedule: